Adam pays $27.70 for 1 marble and 5 stickers.
The marble costs $2.50 more than each sticker.
- What is the cost of 1 marble?
- How much is the cost of 5 marbles and 4 stickers?
(a)
Choose the cheaper item to be 1 u.
Cost of 1 sticker = 1 u
Cost of 1 marble = 1 u + 2.50
Cost of 5 stickers
= 5 x 1 u
= 5 u
Total cost of 1 marble and 5 stickers
= 1 u + 2.50 + 5 u
= 6 u + 2.50
6 u + 2.50 = 27.70
6 u = 27.70 - 2.50
6 u = 25.20
1 u = 25.20 ÷ 6 = 4.20
Cost of 1 marble
= 4.20 + 2.50
= $6.70
(b)
Cost of 5 marbles and 4 stickers
= 5 x 6.70 + 4 x 4.20
= 33.50 + 16.80
= $50.30
Answer(s): (a) $6.70; (b) $50.30